test-lib: use subshell instead of cd $new && .. && cd $old

diff --git a/t/t7604-merge-custom-message.sh b/t/t7604-merge-custom-message.sh
index af53df1c1b0773133dd9883492e286898e60a0c6..9114785ef7c850ae2d393bed3565e13f11339ba0 100755 (executable)
--- a/t/t7604-merge-custom-message.sh
+++ b/t/t7604-merge-custom-message.sh
@@ -40,7 +40,7 @@ test_expect_success 'merge c2 with a custom message' '
        test_cmp exp.subject actual
 '
 
-test_expect_failure 'merge --log appends to custom message' '
+test_expect_success 'merge --log appends to custom message' '
        git reset --hard c1 &&
        git merge --log -m "$(cat exp.subject)" c2 &&
        git cat-file commit HEAD | sed -e "1,/^$/d" >actual &&